Hydraulic dredge



April 14, 1925;

F. A. ROWE HYDRAULIC DREDGE Filed April 1'7, 1922 INVENTOR FREDER/LK Auausrus AowE.

ATTORNE Y5.

Patented Apr. 14, 1925.

FREDERICK AUGUSTUS Rows, or VANCOUVER, BRITISH eo-LuMBiA, cANAnA.

HYDRAULIC DREDGE.

A plication 'file'd April 17, 1922. Serial No. 553,546.

To all 1071 0712 itmay concern:

Be it known that I, Fnnnnnion ArioUsTUs Rown, a citizen of the United States of America and a resident of the city of Vancouver, in the Province of British Columbia, Canada, have invented certain new 'and useful In'iprovennents in'lilydra'ulic' Dredges, of which the following is the specification,

My invention relates to improvcniei'its in hydraulic circulating dredgcs it'or plat-er mining and the drilling of test holes and the like and the object of the invention is to prevent the caving in of the dredged hole and thereby increasing the eliicien'cy and economize working of the dredge and by forming in the water bed a: pocket sealed.

by gravel or silt which naturally .gr a vitates thcreinto keeping the material of thedredge clear at the nozzle so as not to impede the flow of the material as it is discharged and permitting the water to travel freelyto its normal level without interruption and it consists essentially ofa flow pipe centrally disposed within a return pipe, and a cutting and scavenging nozzle at the bottom of the flow pipe having a discharge shoe-communicating with the bottom of the return pipe as hereinafter more particularly explained. Fig. .1. is a. general view of the dredge showing the cutting and scavenging nozzle in use adjacent bedrock of a river bed.

Fig. 2 is a sectional view of the supply head.-

Fig. 3 is a part seetionalvimv ot' the cutting and scavenging nozzle and return pipe shoe. J

In the drawings like (flHHllLtl-PB, oi? reference indicate era-res vending parts in each figure.

.1. represents a connection from the pump or other suitable source of water supply to the supply head 2 which head consists of a casing 23 upstanding from a circular base.

flange 4, the casing 3 being reduced as at 5 and having an orifice 6 at its upper endler the accommodation of the discharge pipe 32, the orifice 6 being provided witha: packing gland 7 to form a watertight oint at the head of the supply head 2. j

8 is a plate having a circular aperture 9 from around which depends an annular rim 10, which rim has an annular rabbet groove 11 flOlHlOCl at its lower extremity engaging the flange l6. Adjacent the outer edges of the plate 8 and oppositely placed is a plurality of rollers 12 suitably pivoted. to the plate 19 is a cover ring. secured to riin IOto' retain the tongue 17 of the flange 1 6 in'li xed position. 20 is the flow pipe of the dredge which is screwed into the sleeve 14 at=its upper end and into the nozzle 2-3 at its lower end. 21 is a guideplate attached to suit; able supports having rollers 22 pivotalliy niountedthereoit to allow for the free vertical movement of the dredge. I represents in general the: cutting and scavenging head which is shown in detail in Fig. in which 2% is abody portion: attached at its upper end to pipe 20. Adjacent the m-id length of the nozzle is an internal anl'iu lair rim 25 on the face of which is a plurality of 'depressions' 26 extending tangentially .diown' wards from the inner edges, each of which terminate in a: tangentialllyand downward lydisposed nozzle 27 extending through the wall of the body 24. The inner periphery of the rim 25 is threaded to'receive: the dis' charge pipe 32 as at 28'.

The lower end of the body is reduced in external diameter and is preferably formed with a: longitudinalconvexity, substantially as shown as at 219 the inner bore of tl'i'eportion 2-9-being substantially sin'rilar to the bore of thereturn pipe 32; Disposed with-in the walls of the portion- 29' is a plurality of apertures 30 each of which is of smallerdiameter than the dischargeor return pipe 32.

- 31 are lug-s projecting fronrthelower portion 29 adjacent the-rims of the apertures 30' for the purpose, of preventing. stones fron i being retained against the apertures through the pressure of the water entering the apertures. 32 is the return pipe which is concentrically mounted within theflow pipe 20 and is at its lower end, screwed into the nozzle 23 its upper end being run through the supply head 2 and packing gland 7 of the same, and terminating in a swivel head as at 33, 34; is a connection leading from the swivel joint 33 to the outlettroni the dredge. 35 represents a stream under which the dredge is working. 36 is a sectional representation of the gap or shaft washed out from the river bed in sinking the dredge and showing the manner in which the gravel tends to cave into the dredged hole. 37 represents the undisturbed gravel and sand of the stream bed and 38 the pocket which is cut by the dredge.

Having thus described the several parts of my invention I will now briefly describe the method of operating the same.

For river dredging it will be preferred to mount the device on a scow or float erecting suit-able guides 13 upon the edges of which the rollers 12 may engage. The water is forced through connection 1, flow pipe and into nozzle 23 from whence it is driven tangentially downwards washing out all gravel and sand from around itself, at the same time the dredge is quickly lowered through the hole thus formed until a desired depth or bedrock is reached It will be apparent that in the average river bed, the thrown up gravel will soon start to fall back into the hole formed by the dredge, irrespective of the size of the hole formedor the pressure of the water used, so that the natural gravitation of the loose sand and gravel into the hole tends to form a cap and arches between the side walls and dredge pipe. On this effect takingplace, the water discharged from the jets 27 continues to impinge the side walls of the hole washing the gravel loose and bringing the sand and pay dirt in its vortex to the bottom centre of the pocket, and that water together with the pay dirt, small gravel and silt is washed upwards through apertures 30 and pipe 32 to It will also be noted that in view of the working pocket being virtually sealed from the river waterthat the several parts of the dredge and the pocket become as a unit, hence the water level in the flow pipe will be similar to that of the return pipe, making it possible to bring up pay dirt, etc., from any depth With a small expenditure of pumping effort. i

A similar mode of operation would obtain in making test holes on dry land, and in case of large stones being encountered bv the downward run of the dredge, the earth from under the stones would be cut away until the stones were allowed to fall to one side to permit the dredge to continue in its downward course.

What I claim as my invention is:

1. In an hydraulic dredge, the combination with the water flow pipe and return pipe located concentrically one within the other, a head forming a chamber into which the water flow pipe is secured and leads, a nozzle into which the return pipe extends and forming the lower portion of the head having laterally directed openings and tangentially setnozzles communicating respectively with. the interior of the lower head and return pipe and with the interior of the upper head and water flow pipe 2. In an hydraulic dredge, the combination with a water flow pipe and discharge duct located concentrically one within the other, a head forming a chamber into which the water flow pipe is secured and leads, a

nozzle into which the discharge duct extends formed with laterally directed openings communicating with the interior of the discharge duct and a series of tangentially set nozzles communicating with the aforementioned chamber and water flow pipe and vertical guiding means by which the device is carried.

3. A dredge comprising a cutting head provided with a hollow chamber and with a central bore leading downwardly from the bottom of the chamber to the lower end of the head, said bore having lateral inlet openings formed in the wall thereof below said chamber, a return pipe connected with the upper end of said bore, a flow pipe surrounding the return pipe and connected with the upper end of said chamber, and a plurality of outwardly directed nozzles formed in the Wall of the chamber at the bottom thereof.

Dated at Vancouver, B. C. this 24th day of March, 1922.

FREDERICK AUGUSTUS ROIVE.

Witnesses J. J. JOHNSTON, ERNEST E. CARVER. 

